摘要：In an attempt to develop potent antitumor agents,new rhodacyanine analogues containing the pyridinium ring（5a-5h）,the isoquinolinium ring（6a-6c） and the quinolinium ring（7a-7e） linked to the rhodanine ring via N-N covalent bond were designed, synthesized and evaluated for antitumor activity against human lung cancer cell line（H460） by MTT assay in *** of the tested compounds showed enhanced antitumor activity with IC_（50） values ranging from 0.006 to 9.2 u,mol/L as compared to the lead compound *** them,the most promising compound 7d（IC_（50） = 0.006μmol/L） was 216.7 times more active than MKT-077（IC_（50） = 1.3μmol/L）.The preliminary structure-activity relationship of the target compounds was discussed.

摘要：A novel series of 5H-pyridazino[4,5-b]indoles were designed and synthesized in order to find novel potent anticancer compounds. The structures were confirmed by ^1H NMR and MS. Their antiproliferative activities against two cancer cell lines were tested by the MTT method in vitro. Three of compounds （1e, 1g, and 1h） exhibited potent antiproliferative activities, especially compound lh （with IC50 values of 5.2 μmol/L and 1.9 μmol/L against Bel-7402 and HT-1080, respectively）. The preliminary structure-activity relationships of 5H-pyridazino[4,5-b]indole derivatives were discussed.

摘要：In our efforts to identify novel potent anticancer agents, we synthesized a series of 2,7-disubstituted triazolo[1,5-a]pyrimidines （6-16）. Their antiproliferative activity against Bel-7402, HT- 1080 and WI-38 cell lines was tested by MTT assay in vitro. Four of the compounds （9-11 and 16） displayed promising antiproliferative activity superior to gefitinib, especially compound 9. A preliminary SAR study of these derivatives was performed.

摘要：A new series of diaryl urea derivatives bearing N-acylhydrazone moiety were designed and synthesized. All the target compounds were evaluated for their antiproliferative activities against human leukemia cell line （HL-60）, human lung adenocarcinoma epithelial cell line （A549） and human breast cancer cell line （MDA-MB-231） in vitro by standard MTT assay. The pharmacological results indicated that some compounds exhibited promising antitumor activities. Compound 1j showed the most potent antiproliferative activity against the tested three cell lines with IC50 values of 0.13 μmol/L, 0.7 μmol/L and 0.5μmol/L, respectively.

摘要：STEM教育是过几年就冷下去的教改运动吗?不是。但是,作为聚焦国民科技创新素养培养的STEM教育,如果离开了自身的专业化和现代化,将无法生存和成熟。成熟的STEM教育需要具备四个外部特征——问题解决、创中学、设计制造和协作探究,以及两个内部特征——S.T.E.M.知识真实的整合性的应用和科学精神的熏陶与强化。这种STEM教育会是一种全新的教育实践,它需要零起点开发的,数字化、标准化和结构化的,包含教学详案的课程产品,需要“用教学过程说明自身”的教学评价方式,需要专业化的人力资源配置,需要全新的教育产业链。在理论上,STEM教育并不需要旧教育学(Pedagogy),它需要的是新教育学(Educology)。在新教育学的引领下,当下的STEM教育运动是一场教育现代升级转型的机会。

摘要：探索土木工程专业学生实践能力提升的路径,以提高学生的实践能力,使学生达到工程教育专业认证提出的“解决复杂工程问题”的能力要求,更好地服务地方社会经济发展。通过对学生、企业技术人员发放调查问卷,分别对学生的实践能力进行自评、第三方评价,找出学生实践能力的弱项,有针对性地进行改进。对于实践能力强的学生,因材施教,采用创新“3+1”培养模式,实现学生实习、就业的连贯,提高就业质量。针对毕业设计环节,联合省内其他高校的土木工程专业进行联合毕业设计,各高校取长补短,共同提高学生的实践能力。

摘要：针对永磁同步电机(permanent magnet synchronous motor,PMSM)传统模型预测磁链控制(model predictive control,MPFC)系统稳态误差大、参数鲁棒性较差的问题,提出了一种基于定子磁链预测误差矢量分析的永磁同步电机多电压矢量选择方法。首先,在两相静止坐标系下依据轴线划分扇区,制定了判断磁链误差矢量所在区域的多电压矢量选择标准。然后,采用定子磁链预测值和两相静止坐标系定子磁链价值函数计算各电压矢量作用时间,改进了传统模型预测寻优过程。此外,设计了一种考虑电阻、电感参数失配的离散滑模定子磁链观测器,进一步提升了系统的参数鲁棒性。最后,通过仿真和实验验证了本文所提预测定子磁链控制方法的有效性和可行性,系统在参数失配情况下仍具有良好的稳态性能,显著减小了定子磁链与电磁转矩脉动。

摘要：针对两级式车载充电机的后级全桥LLC谐振变换器,根据锂电池充电策略确定了电压电流双单环竞争的控制方案,并使用PFM+Burst混合控制方法提高LLC谐振变换器的轻载效率。采用等效电路法简化LLC谐振变换器的小信号模型,推导出开关频率到输出电压的传递函数,基于此设计了2p2z型补偿器用于LLC谐振变换器闭环控制。并在全桥LLC谐振变换器实验平台验证了控制方案的正确性。实验表明,该控制方案下变换器工作稳定,恒压恒流输出准确。

摘要：The fuel consumption associated with some interplanetary transfer trajectories using chemical propulsion is not affordable. A solar sail is a method of propulsion that does not consume fuel. Transfer time is one of the most pressing problems of solar sail transfer trajectory design. This paper investigates the time-optimal interplanetary transfer trajectories to a circular orbit of given inclination and radius. The optimal control law is derived from the principle of maximization. An indirect method is used to solve the optimal control problem by selecting values for the initial adjoint vari- ables, which are normalized within a unit sphere. The conditions for the existence of the time-optimal transfer are dependent on the lightness number of the sail and the inclination and radius of the target orbit. A numerical method is used to obtain the boundary values for the time-optimal transfer trajectories. For the cases where no time-optimal transfer trajectories exist, first-order necessary conditions of the optimal control are proposed to obtain feasible solutions. The results show that the transfer time decreases as the minimum distance from the Sun decreases during the transfer duration. For a solar sail with a small lightness number, the transfer time may be evaluated analytically for a three-phase transfer trajectory. The analytical results are compared with previous results and the associated numerical results. The transfer time of the numerical result here is smaller than the transfer time from previous results and is larger than the analytical result.

摘要：智能功率模块(IPM)封装往往采用散热片外露的形式以提高其与外部环境的热交换效率。散热片通常是由具有高导热率的框架或者基板(如双面覆铜陶瓷基板)制成。由于陶瓷基板的结构特性,基板外露在塑封体外部一侧的铜层在镀锡过程中不会被锡层覆盖,因此会出现表面变色问题。对具有双面敷铜陶瓷基板的IPM模块的散热片变色现象展开分析,总结了变色的处理方法、预防措施以及各自的优缺点。研究结果表明,在封装工艺设计中,将处理与预防方法相结合,才能有效解决IPM封装中双面覆铜陶瓷基板散热片的变色问题。